Apparatus for guiding the marginal portions of wide and narrow strips of photosensitive material or the like

ABSTRACT

Apparatus for guiding strips of different widths past the exposure window in a photocopying machine has a pair of stationary guide rails which define a passage for entry and proper guidance of a relatively wide strip. Two guide blocks are pivotable about axes which are parallel to the direction of transport of the strips through the passage to move between operative positions in which the blocks reduce the effective width of the passage to that of the width of a relatively narrow strip and inoperative positions in which the blocks do not interfere with the entry and transport of the wide strips. The leader of a wide strip automatically engages and pivots the blocks to their inoperative positions and such blocks tend to assume their operative positions under the action of gravity and/or under the bias of springs.

United States Patent 11 1 Lederer 1 Jan. 23, 1973 [541 APPARATUS FOR GUIDING THE 3,001,680 9/1961 Nitkiewicz 226/l5 MARGINAL PORTIONS 0F WIDE AND 2,737,386 3/1956 Reher ....226/l7 NARROW STRIPS OF PHOTOSENSITIVE MATERIAL OR THE Primary Examiner-Samuel S. Matthews LIKE Assistant ExaminerMichael L. Gellner [75] Inventor: Josef Lederer, 8014 Neubiberg, AnomeyhMwhael S Smker Germany v ['57] ABSTRACT [73] Assignee: AGFA Gevaert Aktiengesellschaft,

Leverkusen, Germany Apparatus for guldmg strlps of d1fferent wldths past the exposure wmdow 1n a photocopymg machme has a Filedi J y 30,1971 pair of stationary guide rails which define a passage for entry and proper guidance of a relatively wide [21] Appl' No" l67749 strip. Two guide blocks are pivotable about axes which are parallel to the direction of transport of the [30] Foreign Application Priority Data strips through the passage to move between operative positions in which the blocks reduce the effective Aug. 6, Germany ..p of the passage to of the of a relative), narrow strip and inoperative positions in which the [52] US. Cl ..355/72 blocks do not interfere with the entry and transport of [51] Int. Cl ..G03b 27/58 the wide strips The leader f a wide Strip automati [58] Field of Search ..355/72, 74, 75; 226/15, 17, Cally engages and pivots the b k to h i i 226/18, 21, tive positions and such blocks tend to assume their operative positions under the action of gravity and/or [56] References Cited under the bias of springs.

UNITED STATES PATENTS 15 Claims, 4 Drawing Figures 3,591,282 7/197l Renold ..355/74 15b 6!? 1 13 776a J 68 16b 775a -9; 1155 tg 17 2 18 APPARATUS FOR GUIDING TIIE MARGINAL PORTIONS OF WIDE AND NARROW STRIPS OF PIIOTOSENSITIVE MATERIAL OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to apparatus for guiding the marginal portions of wide or narrow strips. More particularly, the invention relates to improvements in apparatus for guiding relatively wide or relatively narrow strips past one or more stations where the marginal portions of the strips must be maintained in predetermined positions. For example, the guide apparatus can be used in or with photocopying machines for proper guidance of relatively wide or relatively narrow strips which are provided with layers of photosensitive material past an exposing or copying station where the photosensitive material is exposed to light which has passed through a negative or positive original to produce a reproduction of the image of such original on the strip.

The presently known photocopying machines are normally designed for reproduction of images of relatively narrow or relatively wide strips. Therefore, such machines must be provided with means for properly guiding the marginal portions of wide or narrow photosensitized sheets during travel of such strips past the printing or copying station where the strips are exposed to printing light. Many presently known apparatus which serve to guide the strips must be manually adjusted whenever a relatively wide strip is to be followed by a relatively narrow strip or vice versa. As a rule, such adjustment necessitates the shifting or other manipulation of several parts with attendant losses in time. Moreover, the adjustment must be carried out with considerable care since the appearance of prints is adversely affected if the unexposed margin along one edge of the strip is narrower or wider than the unexposed margin along the other edge of the strip. Many presently known apparatus for guiding strips of paper or like materials are provided with positive masks which consist of opaque material and which must be shifted by hand or exchanged whenever a narrow strip or band is to be processed subsequent to completed processing of a wide strip or vice versa. It was further proposed to employ automatic adjusting means for the guide members of such apparatus. The automatic adjusting means is actuated from a control panel and employs a host of electromagnets, switches and other costly and complicated parts which are prone to malfunction and are much too expensive for use in or with many types of printing, photocopying and like machines.

SUMMARY OF THE INVENTION An object of the invention is to provide a simple, compact, rugged, reliable, long-lasting and inexpensive apparatus which can properly guide strips of paper or other relatively stiff material past one or more stations where the marginal portions of the strips must be maintained in predetermined positions and which can be used for proper guidance of relatively wide, mediumwidth or relatively narrow strips.

Another object of the invention is to provide an apparatus wherein the conversion from proper guidance of a wider strip or band to proper guidance of a narrower strip or band or vice versa necessitates no manual adjustments of one or more parts and wherein all those adjustments which are needed due to a change in the width of transported strips are carried out automatically without necessitating any attention on the part of or assistance by the person or persons in charge.

A further object of the invention is to provide a strip guiding apparatus which can be combined with or incorporated in presently known and existing photocopying, printing or like machines which employ strips of different widths.

An additional object of the invention is to provide a strip guiding apparatus which can be used for proper guiding of strips of two, three, four or more different widths.

The invention is embodied in an apparatus for guiding relatively narrow and relatively wide strips of sheetlike material (for example, paper or another material having a certain amount of stiffness), particularly for guiding strips of photosensitive material or strips which are coated with photosensitive material, during transport past the light-admitting opening in a photocopying machine. The apparatus comprises advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane, a pair of first guide members flanking such portion of the path and defining therebetween a passage which is wide enough for entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of such strips travel along the respective first guide members, at least one second guide member (preferably a pair of second guide members) adjacent to one of the first guide members and movable between operative and inoperative positions in which the second guide member respectively extends into and is located without the passage to reduce, in the operative position thereof, the effective width of the passage to that of strips having a smaller second width, confining means for restricting the second guide member to movements between the operative and inoperative positions in directions substantially normal to the direction of transport of strips in the passage between the first guide members, and scanning means for effecting the movement of the second guide member from the operative to the inoperative position in response to entry of the leader of a strip having the first width into the passage between the first guide members.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved strip guiding apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING:

FIG. 2 is an enlarged transverse sectional view as seen in the direction of arrows from the line I-I of FIG. 1 and illustrates the second guide members of the apparatus in their operative positions;

-FIG-. 3 is a similar transverse sectional view but showing the second guide members in their inoperative positions; and

FIG. 4 is a sectional view as seen in the direction of arrows from the line IV-IV of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Referring first to FIG. 1, there is shown an apparatus for guiding relatively wide strips 19 (FIG. 3) and relatively narrow strips 3 (FIG. 2) of sheet-like material. The reference character 1 denotes a roll or supply of convoluted relatively narrow sheet-like material 3 which is rotatable on a mandrel 2 and from which the material 3 (hereinafter called strip or narrow strip) is transported along a predetermined path by a pair of advancing rolls 6, 7 at least one of which is driven in a manner not forming part of the present invention. The strip 3 is tensioned by a roller 40 mounted on a lever 4 which is fulcrummed at 4b and is biased by a spring 4c which counteracts at least some of the gravity force acting on the tensioning roller 4a. A fixedly mounted deflecting roller 5 is mounted downstream of the tensioning roller 4a to define with the advancing rolls 6, 7 a straight portion of the path for the strip 3. That portion of the strip 3 which extends between the deflecting roller 5 and the nip of the advancing rolls 6, 7 is located in a predetermined plane which, in the illustrated embodiment, is a substantially horizontal plane. The roller 5 and the rolls 6, 7 are respectively mounted upstream and downstream of a copying station CS where the strip 3, which is provided with a layer of photosensitive material, is exposed to printing light issuing from a lamp (not shown) and passing through an objective 9 and thereupon through an opening 9a defined by a window or gate 9b. The thus exposed strip 3 is thereupon collected on a mandrel 8a to form a roll 8 of exposed .material which is ready to be transferred into a developing apparatus, not shown. The details of the photocopying machine which includes the objective 9 form no part of the present invention.

The details of the improved strip guiding apparatus which includes the advancing rolls 6, 7 and the deflecting roller 5 are illustrated in FIGS. 2 to 4. A frame 10 which is mounted at a level above the window or gate 9b (not shown in FIGS. 2-4) has a relatively large central opening 10c which registers with the opening 9a of the window 9b and two smaller openings or recesses 10a, 10b which flank the opening 100 and are outwardly adjacent to the marginal portions 3a, 3b of the narrow strip (see FIG. 2). The recesses 10a, 10b are inwardly adjacent to two stationary first guide members or rails 11, 12 which are mounted on the frame 10 and are spaced from each other by a distance correspond- .ing to the width of the wider strip 19 shown in FIG. 3.

When the narrow strip 3 of FIG. 1 or 2 is replaced with the wide strip 19, the marginal portions 19a, 19b of the wide strip 19 travel along the upper sides of two narrow ledges 10a, 10b which are respectively provided with the aforementioned recesses 10a, 10b and form part of the frame 10. The marginal portions 19a, 19b of the strip 19 are guided by the adjacent vertical edge faces of the guide rails 11, 12 so that the strip 19 is properly centered with reference to the openings 9a and in such a way that the exposed portions of the strip 19 are located exactly midway between two narrow unexposed portions which include the marginal portions 19a and 19b. The exposed portions of the wide strip 19 are determined by the positions of ledges 10a, 10b with reference to the guide rails 11, 12. These guide rails are separably or permanently but preferably fixedly secured to the frame 10 which latter includes the ledges 10a, 10b.

In order to insure satisfactory guidance and centering of narrow strips 3, the apparatus is further provided with two second guide members in the form of blocks 15, 16 which are confined by horizontal shafts 13, 14 for pivotal movement between the operative positions of FIG. 2 and the inoperative or raised positions of FIG. 3. The shafts 13, 14 are parallel with the direction of lengthwise transport of the strip 3 through the passage between the stationary guide rails 11, 12 (see the arrow 67 in FIG. 1) and their purpose is to reduce the effective width of such passage to that of the narrow strip 3. The shafts 13, 14 are respectively mounted in bearing brackets 17, 18 which are mounted on the frame 10 or on another stationary part of the apparatus. As clearly shown in FIG. 2, the blocks 15 and 16 are mounted on the shafts 13, 14 in such a way that they tend to dwell in their operative positions under the action of gravity. During pivotal movement about the axes of the respective shafts 13 and 14, the blocks 15, 16 move in directions which are normal to the direction indicated by the arrow 67; this will be readily understood since the shafts 13, 13a are parallel to the direction indicated by arrow 67.

The blocks 15 and 16 are respectively provided with guide surfaces 15a, 16a which are adjacent to the marginal portions 30, 3b of a properly centered narrow strip 3 in the passage between the guide rails 11, 12 and which are normal to the plane of the strip 3 between the roller 5 and advancing rolls 6, 7 and parallel to the direction indicated by the arrow 67 when the blocks 15, 16 dwell in the operative positions shown in FIG. 2. The lower portions of the blocks 15, 16 then respectively extend into the recesses 10a, 10b of the frame 10. These blocks are further provided with suitably inclined centering surfaces 15b, 16b which are normal V to the plane of the strip 3 in the passage between the guide rails l1, 12 when the blocks 15, 16 dwell in their operative positions. The centering surfaces 15b, 16b make an acute angle with the direction indicated by the arrow 67 and their purpose is to guide the relatively stiff leader (not shown) of a freshly introduced narrow strip 3 in such a way that the marginal portions 3a, 3b of the foremost part of the strip 3 which has the full width are moved into the narrowed passage between the guide surfaces 15a, 16a of the blocks 15, 16 when these blocks dwell in the operative positions of FIG. 2.

The blocks l5, 16 are further provided with suitably inclined scanning faces or cam faces 15c, which extend partly into the recesses 10a, 10b when the blocks dwell in the operative positions of FIG. 2. As shown, the height of the scanning faces 15c, 160, as considered in a direction at right angles to the plane of the strip 3 in the narrowed passage between the guide surfaces 15a, 16a, substantially exceeds the depth of the recesses 10a, 10b so that the upper portions of the scanning faces 15c, 16c extend upwardly and beyond the recesses a, 10b and into the path of the leader (not shown) ofa relatively wide strip 19 when the latter is being threaded through the apparatus so as to be moved into the range of the advancing rolls 6 and 7 and to be thereupon automatically transported along the path which includes the passage between the guide rails 11 and 12. The inclination of the scanning faces c, 160 with reference to the plane of the passage between the guide rails 11, 12 is such that, when at least one of these scanning faces is engaged by the relatively stiff leader of a wide strip 19, the blocks 15, 16 are automatically lifted from the operative positions of FIG. 2 to the inoperative positions of FIG. 3 so that the marginal portions 19a, 19b of the wide strip 19 can travel along the vertical edge faces of the guide rails 11 and 12 to insure proper centering of the wide strip 19 between such guide rails.

The purpose of the recesses 10a, 10b is to permit the blocks l5, 16 to assume such operative positions that even an inclined marginal portion on the leader of a narrow strip 3 cannot dislodge the blocks from their operative positions and that such inclined marginal portion is automatically compelled to enter the narrowed passage between the guide surfaces 15a, 16a, by sliding one of the centering surfaces 15b, 16b. The secanning faces 15c, 160 of the blocks 15, 16 are inclined forwardly and upwardly as viewed in FIG. 2 or 3.

THE OPERATION It is assumed that the mandrel 2 is unoccupied and that a fresh roll 1 with a supply of convoluted narrow strip 3 is to be placed onto the mandrel 2 and is to be transported past the objective 9 to be exposed to light passing through the openings 9a and 100. The leader of the roll 1 of strip 3 is advanced along the underside of the tensioning roller 4a and along the upper side of the deflecting roller 5 and is thereupon pushed along the upper side of the frame 10 while the second guide members or blocks 15, 16 dwell in their operative positions under the action of gravity. The one or the other marginal portion of the leader of the fresh strip 3 will abut against and slide along the guide surface 15b or 16b so that the foremost portion of the strip 3 which has a full width will enter the narrowed passage between the guide rails 11, 12, namely, that portion of such passage which extends between the guide surfaces 150 and 16a. The leader of the strip 3 is thereupon advanced into the nip of the advancing rolls 6, 7 and is automatically transported toward and convoluted on the mandrel 8a to form the roll 8. The advancing rolls 6, 7 can transport the strip 3 in stepwise fashion so that the strip 3 is stationary during exposure of that frame which is in registry with the openings 10:: and 9a.

If the trailing end of the narrow strip 3 has advanced such a way that the marginal portions 19a, 19b travel along the adjacent vertical edge faces of the guide rails 11 and 12 to insure proper centering of the strip 19 at the copying station CS. The centering of the strip 19 (which might be somewhat narrower than the distance between the guide rails 11,12) is till satisfactory if the deviation from the optimum centered position does not exceed half the distance between the guide surface or 16a and the guide rail 11 or 12 in the operative positions of the blocks 15 and 16.

In order to insure that the leader of a wide strip 19 will strike against the scanning faces 15c, 16c of the blocks 15, 16 when such blocks dwell in the operative positions of FIG. 2, the apparatus preferably further comprises a locating device 20 (FIG. 4) mounted upstream of the blocks 15, 16 an defining for the marginal portions 19a, 19b of the wide strip 19 a pair of relatively narrow channels 20a of relatively small height (only one channel 200 is shown in FIG. 4). The height of these channels is preferably substantially less than the height of the scanning faces 15c, on the blocks 15, 16. Since the blocks 15, 16 are preferably small and can be made of a lightweight material (e.g., a suitable synthetic plastic substance), and since the blocks rest on the marginal portions 19a, 19b of the wide strip 19 merely by the action of gravity, they are highly unlikely to scratch and/or to otherwise damage the strip 19.

If desired or necessary, for example, when the strips consist of strongly scratch-resistant material, the action of the force of gravity upon the blocks 15, 16 can be enhanced by suitable springs, for example, by torsion springs TS one of which is shown in FIG. 4. Such springs can be convoluted around the confining shafts 13 and 14 to bias the block 15 in a clockwise direction and to bias the block 16 in a counterclockwise direction, as viewed in FIG. 3. It is further within the purview of the present invention to mount the blocks 15, 16 in such a way that they must be pivoted upwardly toward their operative positions and downwardly toward their inoperative positions. The blocks are then biased to operative positions by springs and are pivoted from such operative positions when the scanning faces 15c, 160 are engaged by the leader of a wide strip 19. The channels 20a defined by the locating device 20 insure that the leader of a wide strip 19 invariably strikes against the scanning faces 15c, 160 of the blocks 15, 16 in their operative positions and pivots the blocks to the respective inoperative positions irrespective of whether the blocks tend to dwell in the operative positions under the action of gravity and/or under the action of one or more springs. Still further, the blocks 15, 16 can be mounted for reciprocatory movement between their operative and inoperative positions. For example, the shafts l3, 14 can be replaced with confining means in the form of dovetailed channels for dovetailed projections on the blocks 15, 16. The channels then extend at right angles to the direction of lengthwise transport of strips 3 or 19 in the passage between the guide rails 11, 12 in order to insure that the blocks are movable at right angles to such guide rails. Springs can be provided to yieldably urge the blocks to move to their inoperative positions in response to engagement between their scanning surfaces l5c, 16c and the leader of a wide strip 19.

FIG. 3 further shows a third guide means including two additional blocks 115, 116 which are respectively mounted adjacent to the guide rails 11 and 12 downstream of the blocks 15, 16 and which, when permitted or caused to assume their operative positions, further reduce the effective width of the passage between the guide rails 11, 12 to less than the distance between the guide surfaces 15a, 16a shown in FIG. 2. The purpose of the blocks 115, 116 (which are preferably mounted for movement between operative and inoperative (shown) positions in the same way as shown and described for the blocks 15, 16) is to insure proper guidance and centering of strips which are narrower than the strip 3. Thus, when the leader of a narrowest strip moves between the guide rails l1, l2 and between the blocks l5, 16 its centering is not affected by such guide members; however, when its leader reaches the centering surfaces 115b, 1l6b of the blocks 115, 116, it is caused to enter the narrowed passage between the guide surfaces 115a, 116a so that the narrowest strip is properly centered by the blocks 1 15, l 16 during travel past the openings 9a and 100. When the leader of the strip 3 moves beyond the guide surfaces 15a, 16a of the blocks 15, 16, it engages the scanning faces 115c, 116c of the blocks 115, 116 and causes these blocks to pivot or to otherwise move to their illustrated inoperative positions to thus allow for unimpeded transport of the strip 3 toward the mandrel 8a. If necessary, the apparatus can comprise a fourth, fifth, etc., pair of blocks which are mounted downstream of the blocks 115, 116 to further reduce the effective width of the passage between theguide rails ll, 12 and to allow for proper centering of strips which are narrower than the distance between the guide surfaces 115a, 116a of the blocks 1 15, 1 16 in the operative positions of these blocks. When the leader of the widest strip 19 is threaded through the apparatus, it causes all of the blocks (15, 16, 115, 116 and one or more additional blocks) to assume their inoperative positions. When the strip 3 is threaded through the apparatus, it causes all blocks but the blocks 15, 16 to assume their inoperative positions, and so on. The number of pairs of guide blocks depends on the desired versatility of the apparatus, i.e., whether the apparatus is intended to properly center two, three, four or more types of strips which differ from each other by the distance between their marginal portions. All of the blocks can be mounted for pivotal movement about the axes of the confining shafts l3, 14 or each pair of blocks can be mounted on separate confining means.

lncertain types'of strip guiding apparatus, it is sufficient' to provide a single block 15 or 16 and/or a single block 115 or 116. If the blocks 16, 115, 116 are omitted, the block 15 can cooperate with the guide rail 12 to center strips having a width which exceeds the width of the strip 3 but is less than the width of the strip 19.

The height of the recesses b, 10c and channels 20a is less than the height of scanning faces c, 16c, 115e, 116a, as considered at right angles to the plane of a strip in the passage between the guide rails 11 and 12.

The improved strip guiding apparatuscan be used not only in photocopying machines but also in many other machines and systems, wherein wide or narrow and relatively stiff strip-shaped materials are to be guided lengthwise and must be properly centered during transport past one or more stations. For example, the apparatus can be combined with or incorporated in printing machines. An important advantage of the improved apparatus is that the conversion from transport of relatively wide strips to transport of relatively narrow strips or vice versa does not require any manual or remote control adjustments of the guide members since the blocks 15, 16 and 115, 116 (and additional blocks,- if necessary) preferably automatically assume their operative positions and are automatically moved to inoperative positions if the width of the introduced strip exceeds the shortest distance between their guide surfaces.

Finally, it is equally within the purview of the invention to provide the apparatus with scanning means which need not be an integral part of or connected with the blocks l5, 16, 115, 116 and/or additional blocks. For example, the apparatus can be provided with discrete scanning devices which are mounted upstream of the foremost blocks l5, l6 and are designed to furnish signals indicating the width of the oncoming strip. Such signals are then transmitted to a suitably servo mechanism which automatically moves to inoperative positions all those blocks which would interfere with proper advance of the freshly detected strip. The discrete scanning devices may employ spring-biased scanning levers and/or electric switches which actuate electromagnets by generating signals which are used for effecting the movement of selected blocks to their inoperative positions or which are indicative that all of the blocks can remain in operative positions if the width of the scanned (narrowest) strip is such that its marginal portions can pass between the guide surfaces on the blocks of the rearmost pair of blocks.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacentto one of said first guide members and movable between operative and inoperative positions in and outside of said passage to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; and scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry into said passage of the leader of a strip having said first width.

2. Apparatus as defined in claim 1, wherein said first guide members are stationary and further comprising a fixed frame supporting said guide members.

3. Apparatus as defined in claim 1, wherein said second guide member has a guide surface which is nearest to the other first guide member in the operative position of said second guide member and along which the respective marginal portions of strips having said second width advance during transport through said passage while said second guide member dwells in said operative position thereof.

4. Apparatus as defined in claim 1, wherein said scanning means is provided on said second guide member and extends into the path of movement of the leader of a strip having said first width when said leader enters said passage while said second guide member dwells in said operative position thereof.

5. Apparatus as defined in claim 4, wherein said scanning means comprises an inclined cam face which is provided on said second guide member and faces the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by said leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof.

6. Apparatus as defined in claim 1, further comprising confining means for restricting said second guide member to movement between said operative and inoperative positions, said confining means comprising a shaft defining for said second guide member a pivot axis which is parallel to said portion of said path and said second guide member being pivotable about said axis between said operative and inoperative positions thereof.

7. Apparatus as defined in claim 6, wherein said second guide member is biased to said operative position under the action of gravity.

8. Apparatus as defined in claim 1, wherein said second guide member is provided with a centering surface which is located in a second plane substantially normal to said predetermined plane at ,least when said second guide member dwells in said operative position thereof and which makes an acute angle with the direction of lengthwise transport of strips in said passage, said centering surface being located in the path of movement of the oncoming leader on a strip having said second width to thereby direct such strip into that portion of said path which extends between the other of said first guide members and said second guide member in the operative position of said second guide member.

9. Apparatus as defined in claim 1, wherein said second guide member is arranged to move from a lower level to a higher level in response to movement from said operative to said inoperative position thereof.

10. Apparatus as defined in claim 1, further comprising a locating device disposed upstream of said second guide member, as considered in the direction of lengthwise transport of strips, and arranged to maintain in said plane at least the leaders of strips having said first width wile said leaders approach said passage.

1]. Apparatus as defined in claim 1, further comprising at least one third guide member adjacent to one of said first guide members downstream of said second guide member, as considered in the direction of lengthwise transport of strips along said path, said third guide member being movable between operative and inoperative positions in and outside of said passage to reduce, in said operative position thereof, the effective width of said passage to that of strips having a third width less than said second width, and scanning means for effecting the movement of said third guide member from said operative to said inoperative position thereof in response to entry into said passage of the leader of a strip having a width exceeding said third width.

12. Apparatus as defined in claim 1, comprising a pair of second guide members each adjacent to a different one of said first guide members and each movable between operative and inoperative positions in and without said passage to reduce, in said operative positions thereof, the effective width of said passage to that of strips having said second width, and a pair of scanning means, one for each of said second guide members.

13. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for the entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacent to one of said first guide members and movable between. an operative position disposed at a lower level and an inoperative position disposed at a higher level to be respectively located in and outside of said passage and to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; confining means for restricting said second guide member to movements between said operative and inoperative positions in directions substantially normal to the direction of transport of strips in said passage; and scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry of the leader of a strip having said first width into said passage, said scanning means comprising a cam face provided on said second guide member and facing the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by said leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof, the height of said cam face, as considered in a direction at right angles to said plane, exceeding the extent to which said cam face is lifted in response to movement of said second guide member from said operative to said inoperative position thereof.

14. Apparatus as defined in claim 13, further comprising a frame supporting said guide members and having a recess for entry of a portion of said second guide member and said cam face in response'to movement of said second guide member from said operative to said inoperative position thereof.

15. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for the entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacent to one of said first guide members and movable between operative and inoperative positions in and outside of said passage, to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; confining means for restricting said second guide member to movements between said operative and inoperative positions in directions substantially normal to the direction of transport of strips in said passage; scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry of the leader of a strip having said first width into said passage; and a locating device disposed upstream of said second guide member, as considered in the direction of lengthwise transport of strips, and arranged to maintain in said plane at least the leaders of strips having said first width while said leaders approach said passage, said locating device defining for the marginal portions of the strips having said first width a pair of channels having a predetermined height, as considered in a direction at right angles to said plane, said scanning means comprising an inclined cam face provided on said second guide member and facing the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by the oncoming leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof, said cam face being located downstream of one of said channels and having in the operative position of said second guide member a height which exceeds said predetermined height. 

1. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacent to one of said first guide members and movable between operative and inoperative positions in and outside of said passage to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; and scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry into said passage of the leader of a strip having said first width.
 2. Apparatus as defined in claim 1, wherein said first guide members are stationary and further comprising a fixed frame supporting said guide members.
 3. Apparatus as defined in claim 1, wherein said second guide member has a guide surface which is nearest to the other first guide member in the operative position of said second guide member and along which the respective marginal portions of strips having said second width advance during transport through said passage while said second guide member dwells in said operative position thereof.
 4. Apparatus as defined in claim 1, wherein said scanning means is provided on said second guide member and extends into the path of movement of the leader of a strip having said first width when said leader enters said passage while said second guide member dwells in said operative position thereof.
 5. Apparatus as defined in claim 4, wherein said scanning means comprises an inclined cam face which is provided on said second guide member and faces the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by said leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof.
 6. Apparatus as defined in claim 1, further comprising confining means for restricting said second guide member to movement between said operative and inoperative positions, said confining means comprising a shaft defining for said second guide member a pivot axis which is parallel to said portion of said path and said second guide member being pivotable about said axis between said operative and inoperative positions thereof.
 7. Apparatus as defined in claim 6, wherein said second guide member is biased to said operative position under the action of gravity.
 8. Apparatus as defined in claim 1, wherein said second guide member is provided with a centering surface which is located in a second plane substantially normal to said predetermined plane at least when said second guide member dwells in said operative position thereof and which makes an acute angle with the direction of lengthwise transport of strips in said passage, said centering surface being located in the path of movement of the oncoming leader on a strip having said second width to thereby direct such strip into that portion of said path which extends between the other of said first guide members and said second guide member in the operative position of said second guide member.
 9. Apparatus as defined in claim 1, wherein said second guide member is arranged to move from a lower level to a higher level in response to movement from said operative to said inoperative position thereof.
 10. Apparatus as defined in claim 1, further comprising a locating device disposed upstream of said second guide member, as considered in the direction of lengthwise transport of strips, and arranged to maintain in said plane at least the leaders of strips having said first width wile said leaders approach said passage.
 11. Apparatus as defined in claim 1, further comprising at least one third guide member adjacent to one of said first guide members downstream of said second guide member, as considered in the direction of lengthwise transport of strips along said path, said third guide member being movable between operative and inoperative positions in and outside of said passage to reduce, in said operative position thereof, the effective width of said passage to that of strips having a third width less than said second width, and scanning means for effecting the movement of said third guide member from said operative to said inoperative position thereof in response to entry into said passage of the leader of a strip having a width exceeding said third width.
 12. Apparatus as defined in claim 1, comprising a pair of second guide members each adjacent to a different one of said first guide members and each movable between operative and inoperative positions in and without said passage to reduce, in said operative positions thereof, the effective width of said passage to that of strips having said second width, and a pair of scanning means, one for each of said second guide members.
 13. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for the entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacent to one of said first guide members and movable between an operative position disposed at a lower level and an inoperative position disposed at a higher level to be respectively located in and outside of said passage and to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; confining means for restricting said second guide member to movements between said operative and inoperative positions in directions substantially normal to the direction of transport of strips in said passage; and scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry of the leader of a strip having said first width into said passage, said scanning means comprising a cam face provided on said second guide member and facing the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by said leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof, the height of said cam face, as considered in a direction at right angles to said plane, exceeding the extent to which said cam face is lifted in response to movement of said second guide member from said operative to said inoperative position thereof.
 14. Apparatus as defined in claim 13, further comprising a frame supporting said guide members and having a recess for entry of a portion of said second guide member and said cam face in response to movement of said second guide member from said operative to said inoperative position thereof.
 15. Apparatus for guiding relatively narrow and relatively wide strips of sheet-like material, particularly for Guiding strips containing photosensitive material during transport past the light-admitting opening in a photocopying machine, comprising advancing means for transporting strips of different widths along a predetermined path a portion of which is located in a predetermined plane; a pair of first guide members flanking said portion of said path and defining therebetween a passage wide enough for the entry and lengthwise transport therein of strips having a relatively large first width whereby the marginal portions of strips having said first width travel along the respective first guide members; at least one second guide member adjacent to one of said first guide members and movable between operative and inoperative positions in and outside of said passage to reduce, in said operative position thereof, the effective width of said passage to that of strips having a smaller second width; confining means for restricting said second guide member to movements between said operative and inoperative positions in directions substantially normal to the direction of transport of strips in said passage; scanning means for effecting the movement of said second guide member from said operative to said inoperative position thereof in response to entry of the leader of a strip having said first width into said passage; and a locating device disposed upstream of said second guide member, as considered in the direction of lengthwise transport of strips, and arranged to maintain in said plane at least the leaders of strips having said first width while said leaders approach said passage, said locating device defining for the marginal portions of the strips having said first width a pair of channels having a predetermined height, as considered in a direction at right angles to said plane, said scanning means comprising an inclined cam face provided on said second guide member and facing the oncoming leader of a strip having said first width in the operative position of said second guide member to be engaged by the oncoming leader and shifted thereby to effect the movement of said second guide member from said operative to said inoperative position thereof, said cam face being located downstream of one of said channels and having in the operative position of said second guide member a height which exceeds said predetermined height. 